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    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        // setTimeout(() => {
        //     console.log("0")
        // }, 0)

        // 同步：1 ,7，2，3,8,4,6,5,0
        // 微：5
        // 宏：0
        new Promise((resolve, reject) => {
            // console.log("1")
            resolve()
        }).then(() => {
            // console.log("2")
            new Promise((resolve, reject) => {
                // console.log("3")
                // resolve()
            }).then(() => {
                console.log("4")
                
            }).then(() => {
                console.log("5")
            })
            // console.log('end');
        }).then(() => {
            console.log("6")
        })
        new Promise((resolve, reject) => {
            console.log("7")
            resolve()
        }).then(() => {
            console.log("8")
        })
    </script>
</body>

</html>